High throughput 3D cancer screening for pre-clinical drug discovery

You can do some pretty amazing research with modern lab hardware! A recent article published in GEN is a perfect example. It shows how you can combine hanging drop plates with high-content imaging to screen anti-cancer drugs using spheroid cultures that better mimic the real 3D structure of tumours.

Need for innovation in the pharmaceutical sector

Such research is indicative of a growing trend in the industry; drug discovery is undergoing dramatic changes caused by the economic downturn, drug pricing pressure, and stricter regulatory requirements resulting in the reduced output of truly new medicines from research and development.

Failures during the late stages of drug discovery are extremely costly. As such, researchers are turning to ever more sophisticated in vitro models to screen drugs before moving into clinical trials.

3D cell cultures as the potential solution to more efficient drug developmen

A promising innovation in drug discovery and toxicity testing are 3D cell cultures. They represent a more physiologically relevant model than 2D cell culture and may help to overcome some of the discrepancies between in vitro and in vivo results.

However, most 3D cell culture technologies have limited automation possibilities and are costly, preventing them from becoming the prime model system for pre-clinical drug discovery. The major limitations for the use of 3D cell-culture in drug development tend to be the lack of:

1) A reproducible and scalable high-throughput screening process

2) Robust and reliable data analysis

The methodological breakthrough

Both of the issues listed above were recently tackled via a proof-of principle drug validation study using an in vitro 3D cancer model. The 3D cell cultures in this experiment, referred to as spheroids, were produced using Perfecta3D® Hanging Drop Plates (3D Biomatrix). High throughput and high content screening and analysis were performed with the acumen® hci imager from TTP Labtech.

The 5 key findings of this study were:

Colorectal carcinoma spheroids are easy to produce

The preparation of multiple 384-well plates of spheroids is quick and relatively straightforward

The spheroids are scalable in their size and highly reproducible

Spheroids have micro-tumour physiology that is similar to tumours in vivo (hypoxic core, proliferation throughout the spheroid, etc.)

High throughput screening in 3D is quick and effective, efficiently highlighting key candidate drugs to focus future efforts on

Data analysis made fast and easy

The unique depth of field provided by the system was sufficient to capture the spheroids without the need for Z-stack assembly, while the rapid quantification of spheroid formation produced robust and reproducible data in as little as 8 minutes per plate.

The utility of the set-up in drug screening was demonstrated with the application of a commonly used anti-cancer drug, Doxorubicin. As expected, the drug significantly reduced cancer cell viability within colorectal carcinoma spheroids, which was clearly visualized and quantified with the imager 24h, 48h and 72h post-drug treatment.

The system allows researchers to put reliable numbers on toxicity effects and the efficacy of drugs, and will likely improve efficiency and accuracy when picking the best preclinical drug candidates for future investigation.

Read more

If you would like to see more of the data from the study or to read about it in detail, please visit the full article here at the GEN website. In addition an application note has recently been published in Nature Methods assessing the effects of RNAi knockdown of several genes on spheroid formation.